additive white gaussian noise (AWGN)

Additive White Gaussian Noise (AWGN) is white noise that is distributed over the channel bandwidth according to the Gaussian distribution curve and constant spectral noise power.

The AWGN noise affects the useful signal on which it is linearly superimposed, hence the term additive. The total signal at the end of the channel is the addition of the amplitude of the input wanted signal and the amplitude of the noise signal.

The channel model is a mathematical model for considering the transmit power, but does not apply to interference, nonlinearities, dispersions or fading.